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12 From ARGOS to Globalstar PMO-3-INT Hamburg 23-24 March, 2006 Early, only some significant points extracted from the temperature profiles were transmitted by mean of ARGOS in real time. In order to have the full resolution profiles, the data transmission system was changed: GSM & Internet systems. The data were transmitted in near-real time, e.g. with a delay of about 12 – 20 hours from data collection. Now, full resolution profiles are transmitted by means of the Globalstar system. Data are transmitted from ships to ENEA MFS-VOS Thematic Data Centre. Satellite allows a TRUE real time transmission. GSM transmission is (probably) less expensive, but it is possible only in near coastal areas. In case of long tracks a delay is expected.

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20 QC procedures Improvements I Data are QC with a unique (improved) NRT procedure and released. The Gaussian filter smoothes too much the raw T values, mainly where dT/dz is significant. Each profile is divided in 3 regions (from the surface down to the seasonal thermocline, thermocline region, bottom), with different Gaussian filter values. The time t 0 at which dT/dz starts is selected: four consecutive t intervals where dT/dz < - 0.1 ºC (nominal XBT accuracy) Temperature values from surface to 3 m depth and last three values,a t the bottom, are eliminated (instead 5 m). PMO-3-INT Hamburg 23-24 March, 2006

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23 Data processing improvement The use the ACQUISITION TIME (fixed increments due to the 10 Hz sampling rate) as free parameter. Then, the order of operations at point 3) in qc procedure has to be inverted. START-UP problem. Systematic difference at the seasonal thermocline depth. The XBT recording system needs time before it measures stable T values (within 0.1 ºC). The observed averaged delay is 0.3 ± 0.1 s. Each profile could be rescaled. NEW FALL RATE COEFFICIENTS seem to be required in Mediterranean for XBTs. The addition of a fine-tuning (based on XBT calibration results) seems to be also possible. The accuracy on T values seems to be dependent on depth and occurring thermal structures. PMO-3-INT Hamburg 23-24 March, 2006 Depth error Accuracy on temperature values